January 30-February 1 Winter Storm

[cyclone77]

27 minutes ago, hawkeye_wx said:

While we've been analyzing the thermals, there is a new unfriendly trend for Iowa.  Some models are now veering the heavy precip farther east into Illinois and bypassing much of Iowa.  The UK has been consistently one of the snowiest models for central to eastern Iowa.  Tonight's run cut out a huge chunk of our precip.

Hopefully that trend ceases and reverses.  

[madwx]

5 minutes ago, Hoosier said:

That March 1999 storm has been at #1 every time I have looked.

Based on xmacis got 5.8 at MSN with that one.  Was the last hurrah of winter that year.  
 

[mimillman]

14 minutes ago, cyclone77 said:

Hopefully that trend ceases and reverses.  

It’s running out of time 

[hawkeye_wx]

00z Euro - The east trend continues.  Central Iowa's snow is fading, but east-central is still good....for now.  This run is also a bit south.

[Hoosier]

Well, would think we'll see LOT pull the trigger on a winter storm watch with the overnight package.  Great consensus on widespread warning criteria amounts and it should pound hard for a time.  Main question would be whether they leave out the bottom tier of counties.  Confidence probably a bit lower there than farther north but should still be sufficient enough confidence for a watch even there, imo.

[Jackstraw]

Just about as bullish an AFD from KIND on not just this system but the next 10 days as I've ever seen.  Especially considering the potential for a backend kitchen sink this weekend.  If the models are still this consistent thru Friday I'll expect to enjoy the initial thump before mother nature fixes the water heater.  Buckle up? 

.LONG TERM /Saturday through Thursday/...
Issued at 312 PM EST Thu Jan 28 2021

The primary focus for the extended will be on the potential for a
high impact winter storm over parts of central Indiana this weekend.
In addition as has been expected since the Fall...this appears to be
the opening salvo to the transition to a much more active weather
pattern that may set the stage for the second half of the winter. An
additional higher impact storm already appears on the horizon near
the end of the forecast period later next week.

A strong upper level low off the Pacific coast today will be the
primary catalyst for our weekend system as its energy kicks onshore
tonight then shifts east into the first part of the weekend. This
system will strengthen as energy aloft phases over the Missouri
Valley Saturday then tracks through the region Sunday. At the
surface...low pressure will eject out of the central Rockies
Saturday morning and move first into the mid Mississippi Valley by
Saturday night and across the Ohio Valley Sunday. The combination of
the upper low and surface wave will result in a complex but potent
winter storm that is set to bring for some the best shot at
accumulating snow so far this winter and really in the last couple
of winters.

Initially...Saturday will start out dry with increasing clouds as
the region remains under the influence of the retreating high
pressure. The location of the high to our east will serve as a
critical component for the first phase of the storm set to begin
impacting the forecast area late Saturday afternoon and especially
Saturday night. A residual cold...dry airmass will still be present
even as the high pressure departs. The surge of isentropic lift that
arrives in tandem with the initial precip should have no trouble
overcoming the dry air and evaporative cooling processes will pull
temps back and make snow the likely predominant precip type at
onset. The lift will be aided by a strong 50+kt low level jet and an
axis of mid level deformation as well. This supports the potential
for a potent front end snow thump that could bring a few inches of
accumulation right out of the gate Saturday evening.

Warm advection will be delayed but closely following the initial
surge of moisture with precip transitioning to a rain/snow mix or
even fully to rain Saturday evening and night from the southwest.
Still high uncertainty on exactly where the transition zone sets up
but likely to be aligned somewhere across the northern forecast area
by daybreak Sunday. As the low shifts across the forecast area
Sunday...much of the forecast area is likely to see a cold rain
before the rain/snow line shifts back late day Sunday through early
Monday where additional snow accumulations are likely to be in play.

A couple of takeaway points with the weekend storm system:
- prepare for a high impact winter storm with travel difficulties
especially late Saturday through early Monday at times
- the eventual location of the transition line will dictate snowfall
accumulations and duration of varying precip types
- ice is not expected to be a concern...precip should largely be in
the form of snow and rain
- this has the potential to be the highest impact winter storm to
effect central Indiana in terms of potential snowfall accumulations
in 3 years
- winter weather headlines will likely be needed within the next 24-
36 hours as more model consensus narrows down the details

For the remainder of the extended through the first half of next
week...expect largely quiet weather in the wake of the weekend
storm. Strong high pressure will enable a cold airmass to establish
with potential for any snow cover to impact how cold temperatures
get. This could have an influence on the next storm system in the
pipeline set to impact the Ohio Valley Thursday and Friday. Trends
with that storm support more of a lake cutter with warmer air
advecting into central Indiana...but the presence of the residual
cold air from earlier in the week could create some icing concerns
from that system initially with rain and convection later on. Still
several days away from hammering down specifics but something to
watch going into next week. Buckle up.

[dilly84]

57 minutes ago, hawkeye_wx said:

00z Euro - The east trend continues.  Central Iowa's snow is fading, but east-central is still good....for now.  This run is also a bit south.

Good storm, but major difference from 12z and 18z wrt amounts.

[Jackstraw]

6 hours ago, cyclone77 said:

Looking like 6-8" of cement for here/QC. 

Just change your screen name to "I Like Where I'm Sitting" lol  

[Sciascia]

06z NAM kinda drier in terms of snowfall amounts over N IL. It backed off 1 inch 18z to 00z, and now another inch or so from 00z to 6z. Here’s Chicago’s Kuchera (Pivotal) NAM snow amounts since 12z yesterday:

12z: 12.8

18z: 11.5

0z: 10.4

6z: 9.6

[Sciascia]

6z HRRR has this happening between 6pm Sat & Midnight Sat night/Sun:

 

[A-L-E-K]

Most of klot should be good for 7-8, southern counties will taint but will also see heaviest rates at onset, so I think they're ok. ORD looks relatively jackpot and could push 9-10 but overachiever potential feels muted given the limited 4-6 hour window of strong forcing and I don't see more than DAB+ falling outside the initial advection snow.

[Snownado]

3-4" seems like a safe bet for the northern Indy suburbs. I'll take it.

[Baum]

appears we're still on track for a solid 6"- 10" event at first glance.

[Spartman]

06z GFS:

[A-L-E-K]

would be nice to bump the onset up an hour or two here for daylight action, probably not out the question given the nature of advection events

[mimillman]

Bullish

[Chicago Storm]

6z Euro bumped north and a tick wetter for many areas.

 

 

.

[Baum]

6 minutes ago, Chicago Storm said:

6z Euro bumped north and a tick wetter for many areas.

 

 

.

good sign. It was at this point on Sunday(24 hrs out from GO time) with the last event things began the drier trends. It'd be nice to see it hold tight into the lead up with today's runs.

[RyanDe680]

Plumes comfortably averaging 8.5", with 2 now above 12"  

[A-L-E-K]

4 minutes ago, RyanDe680 said:

Plumes comfortably averaging 8.5", with 2 now above 12"  

 

they'll update in an hour or two, definitely a classic 6-10 look

and lol @ mbp1 which consistently shows like no qpf which would be a heck of feet to pull of in this setup

[RyanDe680]

3 minutes ago, A-L-E-K said:

they'll update in an hour or two, definitely a classic 6-10 look

and lol @ mbp1 which consistently shows like no qpf which would be a heck of feet to pull of in this setup

but in it's defense, it gives us 0.50".....  of snow.

[RCNYILWX]

Got the technical discussion out. We've been trying out a shorter initial AFD and then doubling back later.

Sent from my SM-G965U using Tapatalk

[michsnowfreak]

We won't have the thermals issue in Southeast Michigan but obviously the northern extent of the snow is the worrisome issue.  I am wondering if as always it will continue to edge North a bit.

[A-L-E-K]

5 minutes ago, RCNYILWX said:

Got the technical discussion out. We've been trying out a shorter initial AFD and then doubling back later.

Sent from my SM-G965U using Tapatalk
 

this is the goods

[AWMT30]

6 minutes ago, michsnowfreak said:

We won't have the thermals issue in Southeast Michigan but obviously the northern extent of the snow is the worrisome issue.  I am wondering if as always it will continue to edge North a bit.

6z NAM ticked north let's keep the trend going today!! I would atleast like 3-5" 

[michsnowfreak]

Just now, AWMT30 said:

6z NAM ticked north let's keep the trend going today!! I would atleast like 3-5" 

The latest runs were good except euro. 

[AWMT30]

Just now, michsnowfreak said:

The latest runs were good except euro. 

Even the 6z Euro brought a little more snow to the area 

[fyrfyter]

Euro looks good to me. Today is the 740th day since we have not had more than 2.5” of snow in a 24 hour period.

[Castaway]

On 1/27/2021 at 8:27 PM, CoachLB said:

Just coming on shore tonight isn’t it.

 

On 1/27/2021 at 8:30 PM, Chicago Storm said:

Friday morning.

[cyclone77]

DVN going with 7:1-10:1 LSR for the cwa which sound pretty solid.  I will say that LSRs could be briefly much higher in the first enhanced band.  Wouldn't be surprised to see large flakes with that add up very quickly.  Gonna ride the 6-8" call but wouldn't be surprised if totals are more than that, especially a bit northeast of here.